Clinicopathological and immunohistochemical features of a sebaceous carcinoma arising within a benign dermoid cyst of the ovary

Abstract

Pure sebaceous neoplasms arising in dermoid cysts of the ovary are exceedingly rare. A 63-year-old female with abdominal swelling and pain underwent a right salpingo-oophorectomy that showed a unilocular cyst weighing 830 g and measuring 15x12x10 cm, filled with sebaceous material containing a few hair shafts. The cyst wall exhibited plaques protruding into the cavity of the cyst. Microscopy revealed a dermoid cyst with nests and lobules of atypical and infiltrating sebaceous cells surrounded by basaloid cells. The tumor cells stained diffusely for high-molecular-weight cytokeratins and focally for cytokeratin 7, cytokeratin 19, epithelial membrane antigen and carcinoembryonic antigen in the immunohistochemistry study. Low-molecular-weight cytokeratins, cytokeratin 20, vimentin, S100, p63, estrogen receptor, progesterone receptor, p53 and c-erbB-2 were negative in tumoral cells. The proliferative labeling index (Ki67 and proliferating cell nuclear antigen) was low. Basal cell carcinoma with sebaceous differentiation and sebaceoma must be considered in the differential diagnosis. However, the presence of obvious malignant sebaceous differentiation in nearly every tumor nest and lack of peripheral palisading and peri-tumoral myxoid stroma excluded these diagnoses. Some histogenetic concepts relevant to this case are discussed along with a brief review of this neoplasm. To our knowledge, this is the sixth case report of a sebaceous carcinoma arising in a mature cystic teratoma of the ovary.

A Case of Sebaceous Carcinoma Arising within a Benign Ovarian Cystic Teratoma

“…Sebaceous epithelioma and basal cell carcinoma with sebaceousdifferentiationmustbeconsideredinthedifferential diagnosis.Thepresenceofobviousmalignantsebaceousdifferentiationinnearlyeverytumornestandlackofperipheral palisadingandperi-tumoralmyxoidstromaexcludethesediagnoses.Moreover,thelobulatedgrowthpatternwithpushing ratherthaninfiltrativebordersandthematuresebaceouscells dominatingoverbasaloidcellsarehelpfulmorphologicalfeaturesforthediagnosisofasebaceousepithelioma [6][7][8].Since expression of EMA is exceptional in basal cell carcinomas, focalEMAstaining,asinourcase,isusefulindistinguishing sebaceouscarcinomasfrombasalcellcarcinomas.…”

“…Some authors believe that they originate from pluripotent stem cells, while others suggested that they may originate from more differentiated sebaceous cells in mature teratomas that undergo malignant change rather than from stem cells [8]. Additionally, mutational inactivation of the p53 gene may be involved in the malignant change of sebaceousneoplasmsand,inassociationwithlowproliferativerate (Ki67),mayberelatedtofavorableoutcome [8].Overexpressionofc-erbB-2isfoundin83%ofsebaceouscarcinomas,but isnotassociatedwithanyspecificpathologicalfindingsorclinicaloutcome.Hormonalreceptorsaredetectableinupto22% ofsebaceouscarcinomas,suggestingahormonalinfluenceon these neoplasms [8]. In the present study, c-erbB-2, estrogen andprogesteronereceptorswerenegative,whereasthemitotic indexKi67waspositivefor20%oftheneoplasticcells.…”

“…None of the sebaceous carcinomas arising in mature ovarian teratomas reported until now developed recurrence or metastasis, suggestingthatthiscarcinomahasafavorableoutcomeatdifferentstagesofdiagnosis [3][4][5][6][7][8].…”

“…Squamous cell carcinoma is the most common malignantcomponentfound,correspondingtoupto80%of neoplasms, and the prognosis is poor [2]. However, several malignancies have also been reported, including adenocarcinomas, adenosquamous carcinomas, undifferentiated carcinomas,sarcomas,carcinosarcomasandmelanomas.Casesof puresebaceouscarcinomasareexceedinglyrarelyreportedin theEnglishliterature [3][4][5][6][7][8].…”

“…Thereareonly6reportsofsebaceouscarcinomaarisingwith-in a benign teratoma of the ovary [3][4][5][6][7][8]. We present an additionalcasealongwithabriefreviewoftheliteratureonthis rareneoplasm.…”